The present invention relates to a surface inspection apparatus and a surface inspection method of a subject to be inspected, and relates for example to a wafer surface inspection apparatus and a wafer surface inspection method for inspecting for foreign particles or foreign matter, defects and the like on a semiconductor wafer surface in a manufacturing process of a semiconductor device.
In a manufacturing process of a semiconductor device, a circuit is formed by transferring a pattern onto a bare wafer and etching the same. In the manufacturing processes of various semiconductor devices during which circuits are formed, foreign particles adherent to the wafer surface, defects and the like become major factors causing a decrease in yield. The foreign particles adherent to the wafer surface and the defects are managed in each manufacturing process, and a wafer surface inspection apparatus detects the foreign particles adherent to the bare wafer surface, the defects present on the wafer surface and the like with high sensitivity and with high throughput.
The methods of inspecting for foreign particles and defects on the wafer are largely classified into those using a charged particle beam such as an electron beam or the like and those using light. The methods using light include one that uses a camera to take an image of the wafer surface to analyze the image information, and one that uses a light receiving element like a photomultiplier tube to detect scattered light on the wafer surface to analyze the degree of scattering of light. For example, in a surface inspection apparatus of the type irradiating the surface of the wafer with a laser beam, the scattered light from foreign particles caused by irradiation with the laser beam is detected by a detector and is subjected to analog-to-digital conversion to be output as coordinate data. To increase the throughput of inspection, an inspection table with a work (wafer) mounted thereon is rotated at high speed, and a stage mounted with the inspection table is scanned horizontally in an axial direction. As a surface inspection apparatus of this type, one described in JP-A-55-102233, for example, is known.